Bag venting device for valve bag filling machines

ABSTRACT

A pair of fingers are located immediately below the spout. They are mounted on a vertically sliding yoke, which has side rails engaging in grooves formed in vertical guides. The guides are mounted on the plate which supports the spout, one guide on each side of the spout. An air cylinder pushes the yoke down so that the fingers will engage the valve opening of a bag suspended from the spout and stretch the opening to permit air to escape from the bag. The fingers when extended also clamp the bag to the spout.

United States Patent Lau [ 1 Feb. 29, 1972 BAG VENTING DEVICE FOR VALVEBAG FILLING MACHINES Erwin M. Lau, Bolton, 111.

Black Products Co., Chicago, 111.

Oct. 14, 1970 Inventor:

Assignee:

Filed:

Appl. No.:

U.S.Cl. ..l4l/68, 141/93, 141/310, 141/314 Int. Cl. ..B65b 3/10, B65b 3/17 Field of Search 141/10, 50, 52, 67, 68, 93, 141/114, 285-310,311-317, 390

References Cited UNITED STATES PATENTS Andreas ..141/310 Andreas ..141/310 Primary Examiner-Houston 8. Bell, Jr. Attorney-label Baker York andJones [57] ABSTRACT A pair of fingers are located immediately below thespout. They are mounted on a vertically sliding yoke, which has siderails engaging in grooves formed in vertical guides. The guides aremounted on the plate which supports the spout, one guide on each side ofthe spout. An air cylinder pushes the yoke down so that the fingers willengage the valve opening of a bag suspended from the spout and stretchthe opening to permit air to escape from the bag. The fingers whenextended also clamp the bag to the spout.

7 Claims, 6 Drawing Figures PATENTEDFEB 29 I972 SHEET 1 BF 2 IN VEN TORERWIN M. LAU W ATT'YS.

PATENTEDFEBZS I972 SHEET 2 BF 2 IN VEN TOR ERWIN M. LAU egfl /w ATTYS.

BAG VENTING DEVICE FOR VALVE BAG FILLING MACHINES material, such asplastic, it is necessary to vent the bag in order to permit the fillingair to escape.

The means for causing the material to be packed to flow horizontallyfrom the chamber in the bag filling machine through the spout and intothe bag requires the use of considerable amounts of air. In the case ofpowders and certain flaky and granular materials, the material isfluidized to cause this horizontal movement. With other granularmaterials, including pellets, fluidizing may not be necessary becausethe a pressure in the chamber is effective to move the materialhorizontally through the spout. In some cases an air jet located in thechamber, close to the outlet, is used to set the material in motion. Inall of these flow imparting arrangements, there is considerable amountof filling air which passes through the spout with the material andwhich must be removed from the bag.

It has previously been proposed to use a double spout, the annular spacebetween the inner and outer spout sewing as .a vent passageway.

In the case of granular materials, the particle size of which approachesthe width dimension of the annular space, the particles may be blowninto the vent passageway and become jammed therein.

Other disadvantages of the double spout arrangement are that the overalldiameter of same is so large with respect to the 4 valve opening of thebag as to impede rapid bag placement on the spout, and no matter howlarge the overall diameter, the inner filling tube will be of a smallerdiameter, the inner filling tube will be of a smaller diameter than theouter diameter of a more rapid filling and looser fitting single spout.

According to my invention, I provide a pair of fingers which lieadjacent a single spout of a diameter such that the valve opening of thebag can be fitted over the same very rapidly. Then, after the bag is inplace, the fingers are shifted away from the spout to stretch the valveopening downwardly to provide a space or vent passageway beneath thespout through which the filling air can be vented.

The space or vent passageway is of generally rectangular cross sectionof substantial dimension; if any material particles should become lodgedtherein, they would drop to the floor upon removal of the bag.

By providing an actuator, such as an air cylinder which puts a definiteloading on the fingers, the venting mechanism also serves as a bagclamp. Thus my invention provides a single mechanism which both ventsthe bag and holds it in place on the spout. In order to develop theproper clamping force, I mount the finger assembly in guides so that thefingers will remain parallel to the spout axis when in extendedposition. Thus the clamping action is distributed uniformly along thelength of the flap or sleeve of the valve opening.

Other objects, features, and advantages of my invention will becomeapparent as the description proceeds. In the drawings:

FIG. 1 isa side elevation of a portion of a bag filling machineembodying my invention;

FIG. 2 is an enlarged side elevation view of the bag venting means shownin FIG. 1 taken along line 2-2 of FIG. 4;

FIG. 3 is a front-view of FIG. 2;

FIG. 4 is a plan view of FIG. 2 along line 4-4 of FIG. 2 with certainparts omitted for the sake of clarity, and the spout being shown only inbroken lines;

FIG. 5 is an enlarged detail plan view of the finger means; and

FIG. 6 is a vertical section taken alongline 6-6 of FIG. 5.

With reference now to FIG. 1, the bag filling machine comprises themachine framework 10 which supports a chamber 11 adapted to receive thematerial to be fed into the bags. A bag supporting spout l2 communicateswith the lower end of the chamber 11 and is mounted at the upper end ofa spout supporting frame 13. The spout supporting frame may also serveas a support for other equipment not shown, such as a 7 bag saddle.

The spout supporting frame 13 is connected at 130 to suitable scalemechanism 14, such as that shown in my eopending application, Ser. No.799,356, filed Feb. I4, 1969, now US. Pat. No. 3,540,539 Since the spoutsupporting frame 13 has relative vertical movement with respect to themachine framework 10, a flexible connection is provided between thespout I2 and the chamber 11 in the form of a rubber tube 15.

A valve-type bag 16 is slipped over the spout 12 to receive 1 materiallocated in the chamber 11.

Means are provided to cause material to flow horizontally through thetube 15 and spout 12 into the bag 16. Such means are shown by way ofexample in FIG. I as a fluidizing pad 17 located in the lower part ofthe chamber 1 I, and connected to a filling air supply pipe 18, but itis understood that other means such as an air jet or air pressureapplied to the top of the chamber may be substituted.

A spout valve in the form of an air actuated pinch valve 19 engages therubber tube 15 to cut off the flow of fluidized material through thespout when the contents of the bag reach a predetermined weight, such aspounds.

The spout supporting frame 13 includes a spout mounting plate 20 havinga collar 21 which surrounds the spout 12. The spout 12 extends throughthe opening provided by the collar and is centered in the opening byspacers 22.

Bracket 23 extends upwardly from the spout mounting plate 20 and carriesan air cylinder 24 thereon. Vertical guides 25 extend forwardly from theplate 20, as shown in FIG. 4.

My invention provides finger means 26 which extend forwardly from theplate 20 and which is adapted to be received with the valve opening 27of the bag 16 along within the spout 12 when the bag is placed on thespout. The construction of the valve opening varies with different typesof bags, but generally it is either a flap or a separate sleeve which isdesigned to flatten out as the bag fills up and is removed from thespout so as to provide a closure for the opening. For the purpose ofillustrating the operation of my invention, the separate sleeve type ofvalve opening is shown herein, which appears as a dot and dash linerectangle in FIG. 2.

Finger mounting means in the form of a yoke 28 is located between theguides 25 and confined to vertical movement thereby. In the normalposition, the finger means 26 are located adjacent the spout 12 tofacilitate entry within the valve opening 27 of the bag. The aircylinder 24 has a piston 1 rod 29 the lower end of which is secured tothe top of the yoke 28. When the air cylinder 24 is operated, the yoke28 and the finger means 26 are moved downwardly into the dotted lineposition shown in FIGS. 2 and 3, so that the valve opening 27 isstretched into its open position to permit venting of air from the bagas hereinafter described.

The yoke 28 also includes side rails 30 which are engaged by grooves 31in the guides 25. Each side rail 30 has an inwardly extending horizontalarm 32 for supporting the finger means 26. As shown in FIG. 4, thefinger means is a U-shaped structure made of rod stock having two legs33 and a connecting portion 34. The arms 32 at their inner ends providea half round concave edge which receives the inner end of each of thelegs 33, which are welded thereto, thus providing a rigid mounting forthe finer means 26.

The valve opening 27 is placed over the spout l2 and the finger means 26whet latter is in its solid line position, as shown in FIGS. 2 and 3. Astop plate 41 mounted at the lower end of the yoke 28 defines the properposition of the bag on the spout. valve opening pinch valve removed fromAs soon as the bag filling cycle is initiated by the opening of thepinch valve 19, the control means governing the air supply to the pinchvalve also supplies air to the connection 35 at the top of the aircylinder 14 to actuate same into the lowered dotted line position shownin FIGS. 2 and 3. Thus a space 36 is provided in the lower part of thevalve opening 27, the space being defined by the lower surface of thespout 12 and the legs 33 of the finger means 26. The filling air isvented through this space 36. Then at the conclusion of the bag fillingcycle, as determined by the tripping of the scale means 14, the pinchvalve 19 is closed, and actuating air is supplied to the lowerconnection 37 of the cylinder to elevate the piston rod and the fingermeans 26 back to the normal position. This permits the bag to be removedfrom the spout l2.

The throw of the piston 29 is greater than the vertical dimension of thespace 36 so that the size of the valve opening 27 determines the extentof the downward movement of the finger means 26. Thus the force appliedto the piston, which may be of the order of 100 to 150 pounds, is, inturn, applied to the sleeve forming the bag opening 27. This force, ifuniformly distributed along the length of the sleeve 27 is sufficient tohold the bag in position on the spout without tearing the sleeve orother part of the valve opening 27. The reaction of the sleeve on thefinger means would ordinarily develop a torque on the piston rod andfinger assembly which would tilt same and concentrate the clamping forat the front edge of the valve opening 27, and possibly tear same. Inthe construction shown, this is avoided by the sliding engagementbetween the side rails 30 of the yoke and the groove 31 of the guideswhich takes up the torque and maintains parallelism between the fingerlegs 33 and the spout axis in all positions. To summarize the foregoing,the air pressure provides a definite loading on v the fingers which notonly stretches the valve opening but also clamps the bag on the spout,eliminating the need for a separate bag clamp. Then, as the materialflows through the spout and into the bag, the filling air flows outthrough the space or passageway 36, and through the collar 21 into adust collector 42 (FIG. 1) located on the framework just behind thecollar 21. I

At the conclusion of the bag filling operation, when the pinch valve 19is closed, there will be a certain amount of material contained withinthe spout, and some of this drops off into the bag 16.

Due to the concavity of the lower edge 40 of the spout as projected on ahorizontal plane, the amount of this dribble will vary from time to timein a random manner when packing granular materials and pellets.

I have found that a greater uniformity in the amount of dribble whichoccurs can be maintained if the connecting portion 34 of the fingermeans serves as a partial barrier or dam at the end of the spout 12.Thus the material within the spout will tend to seek an angle of reposewith respect to the top of the dam, as indicated by the dotted line 38in FIG. 6. To this end, the connecting portion 33 of the finger means 26is partially slabbed as shown at 39 in FIGS. 5 and 6 to closely overliethe lower edge 40.

lclaim:

I. In a bag filling machine having a chamber, a horizontally extendingbag filling spout adapted to receive the valve opening of a valve bag,said spout being connected with the lower part of said chamber, meansfor supplying filling air to said chamber to cause material in the lowerpart of said chamber to flow horizontally through said spout and into abag suspended therefrom, spout valve means for controlling the flow ofmaterial through said spout, and mounting means for said spout, thecombination of horizontal finger means extending forwardly from saidspout mounting means, means mounting said finger means for verticalmovement between a first position located adjacent said spout and asecond position in which said finger means is spaced away from saidspout, and actuating means operative, when a bag is positioned on saidspout and said spout valve means is opened, to move said finger meansfrom said first position into said second position in which said fingermeans engage the valve opening of said bag and stretch same to permitsaid filling air entrained in the material flowing through said spout toescape from said bag through the space between the surface of said spoutand said finger means.

2. A bag filling machine as claimed in claim I which includes fluidizingmeans located in the lower part of said chamber and connected to saidfillin air supply means.

3. Bag venting means for a bag illmg machine having a chamber, ahorizontally extending bag filling spout adapted to receive the valveopening of a valve bag, said spout being connected with said chamber,means for causing material in said chamber to fiow horizontally throughsaid spout and into a bag suspended therefrom, means for controlling theflow of material through said spout, and mounting means for. said spout,comprising guide means on said spout mounting means, yoke means slidablymounted in said guide means, horizontally disposed finger means mountedon said yoke means and extending forwardly therefrom beneath said spout,and actuating means operative, when a bag is positioned on said spout,to move said yoke from a normal position in which said finger means areadjacent said s ut to downwardly displaced position in which said fingermeans engage the valve opening of said bag and tension same to provide apassageway through which said bag may be vented.

4. Bag venting means as claimed in claim 3 in which said finger meanscomprises two horizontally disposed rod like finger elements.

5. Bag venting means as claimed in claim 4 in which said rod like fingerelements comprise the legs of a U-shaped member, the connecting portionof which is horizontally disposed and when in normal position overliesthe lower edge of the open end of said spout to provide a dam therefor.

6. Bag venting means for a bag filling machine having a chamber, ahorizontally extending bag filling spout adapted to receive the valveopening of a valve bag, said spout being connected with the lower partof said chamber, means for causing material in the lower part of saidchamber to flow horizontally through said spout and into a bag suspendedtherefrom, spout valve means for controlling the flow of materialthrough said spout, and a mounting plate for said spout, comprisingguide means on said spout mounting plate providing oppositely disposedgrooves, yoke means slidably mounted in said grooves, a pair ofhorizontally disposed fingers mounted on said yoke means and extendingforwardly therefrom beneath said spout, and pneumatic actuating meansoperative, when a bag is positioned on said spout and said spout valvemeans is opened, to move said yoke from a normal position in which saidfingers are adjacent said spout to a downwardly displaced position inwhich said fingers engage the valve opening of said bag and tension sameto provide beneath said spout a passageway through which said bag may bevented, said tension causing said bag opening to engage the uppersurface of said spout with a force sufficient to maintain said bag inposition on said spout until said tension is relieved.

7. Bag venting means as claimed in claim 6 in which said spout mountingplate includes a collar at least partially surrounding said spout andspaced therefrom, spacer means between said spout and said collar, anddust collector means located behind said collar so that the air ventedfrom said bag will flow through said collar and into said dust collectormeans.

1. In a bag filling machine having a chamber, a horizontally extendingbag filling spout adapted to receive the valve opening of a valve bag,said spout being connected with the lower part of said chamber, meansfor supplying filling air to said chamber to cause material in the lowerpart of said chamber to flow horizontally through said spout and into abag suspended therefrom, spout valve means for controlling the flow ofmaterial through said spout, and mounting means for said spout, thecombination of horizontal finger means extending forwardly from saidspout mounting means, means mounting said finger means for verticalmovement between a first position located adjacent said spout and asecond position in which said finger means is spaced away from saidspout, and actuating means operative, when a bag is positioned on saidspout and said spout valve means is opened, to move said finger meansfrom said first position into said second position in which said fingermeans engage the valve opening of said bag and stretch same to permitsaid filling air entrained in the material flowing through said spout toescape from said bag through the space between the surface of said spoutand said finger means.
 2. A bag filling machine as claimed in claim 1which includes fluidizing means located in the lower part of saidchamber and connected to said filling air supply means.
 3. Bag ventingmeans for a bag filling machine having a chamber, a horizontallyextending bag filling spout adapted to receive the valve opening of avalve bag, said spout being connected with said chamber, means forcausing material in said chamber to flow horizontally through said spoutand into a bag suspended therefrom, means for controlling the flow ofmaterial through said spout, and mounting means for said spout,comprising guide means on said spout mounting means, yoke means slidablymounted in said guide means, horizontally disposed finger means mountedon said yoke means and extending forwardly therefrom beneath said spout,and actuating means operative, when a bag is positioned on said spout,to move said yoke from a normal position in which said finger means areadjacent said spout to downwardly displaced position in which saidfinger means engage the valve opening of said bag and tension same toprovide a passageway through which said bag may be vented.
 4. Bagventing means as claimed in claim 3 in which said finger means comprisestwo horizontally disposed rod like finger elements.
 5. Bag venting meansas claimed in claim 4 in which said rod like finger elements comprisethe legs of a U-shaped member, the connecting portion of which ishorizontally disposed and when in normal position overlies the loweredge of the open end of said spout to provide a dam therefor.
 6. Bagventing means for a bag filling machine having a chamber, a horizontallyextending bag filling spout adapted to receive the valve opening of avalve bag, said spout being connected with the lower part of saidchamber, means for causing material in the lower part of said chamber toflow horizontally through said spout and into a bag suspended therefrom,spout valve means for controlling the flow of material through saidspout, and a mounting plate for said spout, comprising guide means onsaid spout mounting plate providing oppositely disposed grooves, yokemeans slidably mounted in said grooves, a pair of horizontally disposedfingers mounted on said yoke means and extending forwardly therefrombeneath said spout, and pneumatic actuating means operative, when a bagis positioned on said spout and said spout valve means is opened, tomove said yoke from a normal position in whIch said fingers are adjacentsaid spout to a downwardly displaced position in which said fingersengage the valve opening of said bag and tension same to provide beneathsaid spout a passageway through which said bag may be vented, saidtension causing said bag opening to engage the upper surface of saidspout with a force sufficient to maintain said bag in position on saidspout until said tension is relieved.
 7. Bag venting means as claimed inclaim 6 in which said spout mounting plate includes a collar at leastpartially surrounding said spout and spaced therefrom, spacer meansbetween said spout and said collar, and dust collector means locatedbehind said collar so that the air vented from said bag will flowthrough said collar and into said dust collector means.